FprEN 17779
(Main)Organo-mineral fertilizers - Extraction of phosphorus soluble in a neutral ammonium citrate solution
- Abstract
This document specifies the procedure for the extraction of different organic and organo-mineral fertilizers with a solution of neutral ammonium citrate to enable a subsequent determination of phosphorus.
This document is applicable to the fertilizing products blends where a blend is a mix of at least two of the following components: fertilizers, liming materials, soil Improvers, growing media, inhibitors, plant biostimulants, and where the following category: organic fertilizers, organo-mineral fertilizers is the highest % in the blend by mass or volume, or in the case of liquid form by dry mass. If the organic fertilizer or the organo-mineral fertilizer is not the highest % in the blend, the European Standard for the highest % of the blend applies. In case a fertilizing product blend is composed of components in equal quantity, the user decides which standard to apply. Variations in analytical methods for fertilizing product blends can lead to differing results as some components or matrix interactions can affect the outcome. Validation procedures have shown that developed standard methods are robust and reliable across diverse product compositions, but possible interferences and unexpected results when analysing fertilizing product blends are possible.
- Status
- Not Published
- Publication Date
- 17-Feb-2027
- Technical Committee
- CEN/TC 260 - Fertilizers and liming materials
- Drafting Committee
- CEN/TC 260/WG 8 - Organic and organo-mineral fertilizers
- Current Stage
- 4599 - Dispatch of FV draft to CMC - Finalization for Vote
- Start Date
- 27-Aug-2026
- Due Date
- 14-Mar-2027
- Completion Date
- 27-Aug-2026
FprEN 17779 is a CEN draft European Standard for extracting phosphorus from organic and organo-mineral fertilizers with a neutral ammonium citrate solution. It specifies the laboratory procedure used before phosphorus is determined, and it is aimed at laboratories and technical staff working with these fertilizers and related fertilizing product blends.
What does FprEN 17779 specify?
FprEN 17779 specifies the extraction of phosphorus from different organic and organo-mineral fertilizers using neutral ammonium citrate so that phosphorus can be determined afterwards. The document also sets the rules for when it applies to fertilizing product blends and how the document is organized.
The scope covers blends made from at least two component classes such as fertilizers, liming materials, soil improvers, growing media, inhibitors, and plant biostimulants, when the organic fertilizer or organo-mineral fertilizer is the dominant component by mass, volume, or dry mass for liquids. If another component class is dominant, the standard for that dominant class applies; if components are present in equal quantity, the user chooses the applicable standard. The document is arranged in clauses on scope, normative references, terms and definitions, principle, sampling and sample preparation, reagents, apparatus, procedure, and test report, followed by a bibliography.
What are the key requirements of FprEN 17779?
FprEN 17779 is built around a controlled extraction step: phosphorus is removed from the sample with neutral ammonium citrate at pH 7, then the extract is analysed according to prEN 17774. In practice, the method is a preparation step for the final phosphorus measurement, so the extraction conditions need to be followed closely.
- Clause 1 limits use to organic and organo-mineral fertilizers and to qualifying fertilizing product blends. This matters because the user must first decide which standard fits the product matrix.
- Clause 4 sets the principle: extract with neutral ammonium citrate at pH 7, then determine phosphorus in the extract. This means the extraction and the measurement are separate steps.
- Clause 5 places sampling outside the method and requires sample preparation in accordance with EN 1482-2. Recommended sampling methods are given in EN 1482-1 and EN 1482-3. In practice, the result depends on receiving a representative sample that has not changed during transport or storage.
- Clause 6 specifies the reagent quality and the preparation of the neutral ammonium citrate solution. The pH control is important because the extraction strength depends on the reagent being truly neutral.
- Clause 7 lists the required laboratory equipment, including a thermostatic water bath at 65 °C and phosphate-free filter paper. This matters because temperature control and phosphate-free materials help keep the extraction reliable.
- Clause 8 fixes the test portion, extraction time, cooling, dilution, filtration, and timing of the phosphorus determination. For some rock phosphate materials, a larger test portion is used. The extract should be determined the same day, or stored briefly under chilled conditions if needed.
- Clause 9 requires the test report to identify the sample, state the method used, record sampling details when known, note when extraction finished, and document any deviations or incidents. This supports traceability in routine quality control and disputes.
What terms does FprEN 17779 define?
FprEN 17779 uses the vocabulary of EN 12944-1 and EN 12944-2, and it applies these terms in the extraction method.
- Fertilizing product blend - a mix of at least two listed component classes, used here to decide which standard applies.
- Neutral ammonium citrate solution - the pH 7 reagent used to extract phosphorus from the sample.
- Test portion - the weighed amount of laboratory sample placed into the flask for extraction.
- Laboratory sample - the sample received by the lab for analysis.
- Extract - the liquid obtained after extraction and filtration, used for the phosphorus determination.
Who uses FprEN 17779?
FprEN 17779 is used by laboratories that test organic and organo-mineral fertilizers, by manufacturers checking product quality, and by quality managers who need a reproducible phosphorus extraction step. It is also relevant to people preparing samples, running the extraction, and writing the test report for fertilizing products and blends.
What changed in FprEN 17779 from the previous edition?
FprEN 17779 supersedes CEN/TS 17779:2022. The foreword states these significant changes: the Technical Specification was adopted as a European Standard, the title was adapted, an Introduction was added, the Scope was updated to clarify fertilizing product blends and the analytical method to use, Clause 6 on reagents was added, Clause 9 on the test report was added, and the bibliography was updated.
Which standards are used with FprEN 17779?
| Standard | Contribution |
|---|---|
| prEN 17774 | Gives the phosphorus determination step after extraction, using ICP-AES after extraction by water and weak solvents. |
| EN 12944-1 | Supplies general fertilizer and liming materials vocabulary used in the document. |
| EN 12944-2 | Supplies fertilizer-specific vocabulary used in the document. |
| EN 1482-2 | Sets the general provisions for sample preparation. |
| EN 1482-1 | Gives recommended general sampling provisions. |
| EN 1482-3 | Gives sampling provisions for static heaps. |
What does the FprEN 17779 document contain?
FprEN 17779 contains the full laboratory workflow for this extraction method. Clause 6 gives the reagent preparation, including the neutral ammonium citrate solution and the pH check; Clause 7 lists the apparatus; and Clause 8 sets out the test portion, the 65 °C extraction, cooling, dilution, and filtration steps. Clause 9 then states what the test report has to record for traceability and review.
Relations
- Effective Date
- 11-Jun-2025
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Frequently Asked Questions
FprEN 17779 is a draft published by the European Committee for Standardization (CEN). Its full title is "Organo-mineral fertilizers - Extraction of phosphorus soluble in a neutral ammonium citrate solution". This standard covers: This document specifies the procedure for the extraction of different organic and organo-mineral fertilizers with a solution of neutral ammonium citrate to enable a subsequent determination of phosphorus. This document is applicable to the fertilizing products blends where a blend is a mix of at least two of the following components: fertilizers, liming materials, soil Improvers, growing media, inhibitors, plant biostimulants, and where the following category: organic fertilizers, organo-mineral fertilizers is the highest % in the blend by mass or volume, or in the case of liquid form by dry mass. If the organic fertilizer or the organo-mineral fertilizer is not the highest % in the blend, the European Standard for the highest % of the blend applies. In case a fertilizing product blend is composed of components in equal quantity, the user decides which standard to apply. Variations in analytical methods for fertilizing product blends can lead to differing results as some components or matrix interactions can affect the outcome. Validation procedures have shown that developed standard methods are robust and reliable across diverse product compositions, but possible interferences and unexpected results when analysing fertilizing product blends are possible.
This document specifies the procedure for the extraction of different organic and organo-mineral fertilizers with a solution of neutral ammonium citrate to enable a subsequent determination of phosphorus. This document is applicable to the fertilizing products blends where a blend is a mix of at least two of the following components: fertilizers, liming materials, soil Improvers, growing media, inhibitors, plant biostimulants, and where the following category: organic fertilizers, organo-mineral fertilizers is the highest % in the blend by mass or volume, or in the case of liquid form by dry mass. If the organic fertilizer or the organo-mineral fertilizer is not the highest % in the blend, the European Standard for the highest % of the blend applies. In case a fertilizing product blend is composed of components in equal quantity, the user decides which standard to apply. Variations in analytical methods for fertilizing product blends can lead to differing results as some components or matrix interactions can affect the outcome. Validation procedures have shown that developed standard methods are robust and reliable across diverse product compositions, but possible interferences and unexpected results when analysing fertilizing product blends are possible.
FprEN 17779 is classified under the following ICS (International Classification for Standards) categories: 65.080 - Fertilizers. The ICS classification helps identify the subject area and facilitates finding related standards.
FprEN 17779 has the following relationships with other standards: It is inter standard links to CEN/TS 17779:2022. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
FprEN 17779 is associated with the following European legislation: EU Directives/Regulations: 2019/1009; Standardization Mandates: M/564, M/564 AMD 1, M/564 AMD 2. When a standard is cited in the Official Journal of the European Union, products manufactured in conformity with it benefit from a presumption of conformity with the essential requirements of the corresponding EU directive or regulation.
FprEN 17779 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
SLOVENSKI STANDARD
01-marec-2026
Organsko-mineralna gnojila - Ekstrakcija fosforja, topnega v nevtralni raztopini
amonijevega citrata
Organo-mineral fertilizers - Extraction of phosphorus soluble in a neutral ammonium
citrate solution
Organisch-mineralische Düngemittel - Extraktion von Phosphor, der in neutralem
Ammoniumcitrat löslich ist
Engrais organo-minéraux - Extraction du phosphore soluble dans une solution de citrate
d’ammonium neutre
Ta slovenski standard je istoveten z: prEN 17779
ICS:
65.080 Gnojila Fertilizers
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
DRAFT
EUROPEAN STANDARD
prEN 17779
NORME EUROPÉENNE
EUROPÄISCHE NORM
January 2026
ICS 65.080 Will supersede CEN/TS 17779:2022
English Version
Organo-mineral fertilizers - Extraction of phosphorus
soluble in a neutral ammonium citrate solution
Engrais organo-minéraux - Extraction du phosphore Organisch-mineralische Düngemittel - Extraktion von
soluble dans une solution de citrate d'ammonium Phosphor, der in neutralem Ammoniumcitrat löslich ist
neutre
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 260.
If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations
which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC
Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 17779:2026 E
worldwide for CEN national Members.
prEN 17779:2026 (E)
Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Principle . 5
5 Sampling and sample preparation . 6
6 Reagents . 6
7 Apparatus . 6
8 Procedure. 7
8.1 Test portion . 7
8.2 Extraction . 7
9 Test report . 7
Bibliography . 8
prEN 17779:2026 (E)
European foreword
This document (prEN 17779:2026) has been prepared by Technical Committee CEN/TC 260 “Fertilizers
and liming materials”, the secretariat of which is held by DIN.
This document is currently submitted to the CEN Enquiry.
This document will supersede CEN/TS 17779:2022.
Compared to the previous edition, prEN 17779:2026 includes the following significant technical changes:
— the CEN Technical Specification has been adopted as a European Standard;
— title adapted;
— Introduction added;
— Scope (Clause 1) updated including the clarification on fertilizing product blends and the analytical
method to be used;
— Reagents (Clause 6) added;
— Clause 9 (Test report) added;
— Bibliography updated.
This document has been prepared under a Standardization Request addressed to CEN by the European
Commission. The Standing Committee of the EFTA States subsequently approves these requests for its
Member States.
prEN 17779:2026 (E)
Introduction
WARNING — Persons using this document should be familiar with usual laboratory practice. This
document does not purport to address all of the safety issues, if any, associated with its use. It is the
responsibility of the user to establish appropriate health and safety practices and to ensure compliance
with any national regulatory conditions.
IMPORTANT — It is absolutely essential that tests conducted according to this document are carried out
by suitably trained staff.
prEN 17779:2026 (E)
1 Scope
This document specifies the procedure for the extraction of different organic and organo-mineral
fertilizers with a solution of neutral ammonium citrate to enable a subsequent determination o
...